That probably benefits Palin the most. Given that some on her side of the political spectrum raised questions about her readiness for the national stage, a significant miscue could have had a snowfall effect and raised to clamor concerns about her place on the GOP ticket. She avoided that.

Unquestionably, Palin's style and vernacular is unlike any that voters have seen in the television era of U.S. politics. (See video here.) For many, it's refreshing. Still, she had to guard against overplaying the "hockey mom" persona, and for the most part it seemed she did.

Biden had his own stylistic challenge: not come across as a stereotypically long-winded legislator. He displayed these qualities at times -- it's simply a part of who he is -- but not enough to seriously hinder his performance or become a talking point.

During the debate's final moments, both effectively drove home their core messages.

"People aren't looking for more of the same. They are looking for change. And John McCain has been the consummate maverick in the Senate over all these years," Palin asserted, setting aside her folksy nature....

...But Biden was ready, questioning McCain's maverick credentials on several fronts and in a series of well-turned phrases. He summed up succinctly: "He's not been a maverick on virtually anything that genuinely affects the things that people really talk about around their kitchen table."

Bottom line: As enthralling and entertaining as the faceoff often was, it remained a duel between the bottom halves of the tickets. The vast majority of undecideds still can be expected to make voting decisions based on their attitudes toward the top halves.

We'll see how those top halves duke it out next week at the second presidential debate. The town hall style event will take place Tuesday, October 7 at Belmont University in Nashville, Tennessee. We will, of course, be live blogging it.

Thanks for being with us this evening. Goodnight.

7:40 p.m. It’s over! The candidates have thanked Ifill and their families have joined them on stage. Together, the Biden and Palin families sure have a lot of children.

The candidates are now standing in the middle of all of them, chatting quite civilly. It's hard to imagine McCain and Obama doing the same.

7:36 p.m. As Palin gets first crack at a closing statement, she reiterates that it was a pleasure to “finally” meet Biden –- a none-too-subtle way to call attention to her outsider status.

Biden, as he begins his closing remarks, echoes the sentiment, saying, “Governor, it really was a pleasure to meet you.”

He would have been better served, though, by not lowering his chin and seeming to peer down at her as he did so.

7:33 p.m. Biden is known for often displaying his emotion, and he does so when he works into an answer the tragedy he endured shortly after he first won his Senate seat in 1972: the death of his wife and daughter in a car accident. His two young sons, though seriously injured, survived, and Biden said he learned over the next few years what it was like to be a single parent.

As he related the story, he paused, his eyes appearing to moisten somewhat.

He then interjects a gender element into the dialogue, saying he would dispute anyone who would say he couldn’t understand such family stresses because he is a man.

7:23 p.m. With time running out, both candidates seem to suddenly realize that it's time to score their broader points.

Biden, a senator since 1973, is trying to establish his “just folks” credentials by mentioning a restaurant in his hometown in Wilmington, Del., and his childhood roots in Scranton, Penn. Ask anyone in those communities about the last eight years of Republican rule in the White House, he says, and the verdict would be clear: “The middle class has gotten the short end. The wealthy have done very well.”

Palin responds with a line she probably had been prepped to use: “Say it ain’t so, Joe.” She then stressed the “maverick” credentials a McCain-Palin administration would bring to Washington.

Palin is doing her best to appear folksy and down-home. She berated Biden for bringing up the Bush administration by saying, “Doggonit, let’s look ahead!” A few minutes later, she gives a shout-out to her brother's third-grade class (her brother is a schoolteacher), looking into the camera and saying, "You get extra credit for watching this debate!"

She has also been a little self-deprecating, calling her and Biden’s jokes about what a vice president does “lame.” Our Robin Abcarian, who is live in the press room at the debate, reports that that line evoked an angry response from one audience member (it was "a mean cat sound," she said).

7:11 p.m. As the debate enters its last 30 minutes, Palin may have scored by coming back to Iraq and noting that Biden was among the vast majority of senators from both parties who voted -– almost exactly six years ago -– for the resolution authorizing that U.S. military action there.

With a smile on her face, she says this underscores how she’s a “Washington outsider” who doesn’t understand how the politicians in the nation’s capital operate. “Americans voted for the war and now you’re against it. ... Americans are craving that straight talk."

But a few moments later, she stumbles. In midsentence, while talking about what the "pundits" will say about she sees as Biden's double-talk -- she detours and broaches McCain's war experience. It was the first moment in the debate where Palin seemed like the same wide-eyed person Katie Couric sometimes stumped with questions in her series of interviews over the last few weeks.

7:04 p.m. Palin, as she did in her ABC and CBS interviews, stressed her commitment to the security of Israel.

Biden, chairman of the Senate Foreign Relations Committee, gets a little caught in the weeds on the topic of overall tensions in the Middle East. But he eventually gets to what no doubt had been a line honed in debate practices, asserting that the Bush administration’s policies for the region have been “an abject failure.”

Palin, in responding, says: “I’m so encouraged to know we both love Israel.”

6:56 p.m. Palin just said, "There have been huge blunders throughout this administration."

But although she is obviously trying to distance her ticket from George W. Bush, she sure sounds a lot like the 43rd president when she pronounces the word "nuclear." (Both Republicans stretch out the "U" so it sounds like "nuuuclear.")

6:54 p.m. When asked which is a greater threat, nuclear Iran or unstable Pakistan, Biden stresses the dangerousness of Pakistan. Palin hardly addresses Pakistan, probably trying to avoid the mistake she made last week, when she said she would support taking out terrorist targets in Pakistan, a position that sounds more similar to Obama’s view than McCain’s.

6:51 p.m. Turnabout is fair play.

Biden had sought to use Palin’s position on taxing oil companies to zing McCain. As the debate turned to foreign policy, Palin sought to use past differences between Biden and Obama on funding votes in the Senate for the troops in Iraq against the top of the Democratic ticket.

Noting that Biden had been more supportive of the funding measures –- and that, during the Democratic primary fight when they both sought their party’s presidential nomination -– he had criticized Obama on Iraq, Palin said, “I respected you when called him out on that.”

6:47 p.m. The pair make clear the tickets agree on one basic -– opposing a redefinition of marriage to include gay couples.

Biden attempts to clarify whether Palin, who had stressed her tolerance toward homosexuals, agreed that there should be no distinction in civil rights between gay couples and heterosexual ones. She takes a pass on answering that one.

6:43 p.m. As she did in her interviews with ABC’s Charles Gibson and CBS’ Katie Couric, Palin is seeking to set aside the question about what has brought about global warming. Saying part of it is related to man’s activities and part of it is the cyclical nature of weather, she says, “I don’t want to argue about the causes.”

But Biden does. “I think it is man-made” he says of global warming. He adds, in a comment that has potential of being recycled on news shows: “If you don’t understand the causes, it’s virtually impossible to come up with the solutions.”

6:35 p.m. As the debate turns to one of Palin’s strengths on the issue front –- energy policy -– Biden attempts to use her record as Alaska’s governor to score a point against McCain.

He notes –- and applauds –- Palin for supporting windfall profit taxes on oil companies. He urges her to bring McCain, who like most congressional Republicans has opposed such proposals, on board.

6:31 p.m. It was inevitable. Perhaps the only surprise is that it was 20 minutes or so into the debate before Biden invoked a phrase now forever linked to Palin’s home state.

In attacking McCain’s healthcare plan, Biden charged that with the Republican’s proposed $5,000 tax credit that Americans would receive to seek their own coverage, 20,000 people would lose employer coverage with an average value of $12,000. “I call that the ultimate bridge to nowhere,” he said.

6:29 p.m. A quick note on style: The candidates have been turning and looking at each other at the beginning of each answer before they turn and look at the camera to answer. In last week’s debate, McCain caught flack for not looking at Obama. Media lesson learned.

6:25 p.m. After Biden, for the second time in the debate’s first few minutes, stressed the commitment he and Barack Obama have to providing middle-class tax relief, Palin rolled out one of main attack lines she and McCain use against the Democratic ticket. Palin asserted that Obama (whom she referred to as “Barack”) had voted “94 times” to increase taxes or not support a tax reduction.

That claim has been widely disputed by various nonpartisan fact-checking organizations. And Biden responded, “The charge is absolutely not true.”

He added that most of those votes were procedural –- designed to keep the basic budget-making process in Congress operating -- and that McCain had voted similarly.

6:20 p.m. When Ifill asks each nominee what he or she would do as vice president, neither really gives an answer. Instead of saying what they would actually do, Biden and Palin set up the main narratives that we will surely be hearing throughout the night:

Biden tries to paint John McCain as out of touch (he reminds viewers of McCain’s comment two weeks ago that the “fundamentals of the economy are strong”) and Palin casts her and McCain as a couple of “mavericks” who will bring bipartisan change to Washington.

Then Ifill calls them out. “Governor, senator, neither of you really answered that last question about what you would do as vice president," she says. "But we’ll come back to it.”

6:15 p.m. Palin, in responding to the first question about the congressional effort to respond to the nation’s financial crisis, immediately seeks to establish her ties to the vast bulk of Americans.

She says a good way to gauge the public pulse is to check out conversations on the sidelines of soccer games. “I betcha you’re going to hear some fear” in those voices, she says.

Expect Palin to play the “just folks” card again and again.

Indeed, in expanding on who is at fault in the fiscal meltdown, she worked in the phrases “Joe Six Pack” and “hockey moms across the nation.” There have been a bunch of "you betchas" too.

6:04 p.m. The nominees have walked onto stage. Palin, while shaking Biden's hand, asks: "Hey, can I call you Joe?" He laughs and replies, "Yes, of course."

5:52 p.m. Ifill, on crutches, was just helped onto the debate stage. Last week, she broke her ankle due to a misstep on a staircase.

She settled into her seat, turned to the audience and reminded them to turn off their cellphones.

5:45 p.m. Finally, we've arrived at the moment we've been waiting for since late August, when John McCainchoseSarah Palin, the largely unknown governor of Alaska, to be his running mate. Welcome to the 2008 vice presidential debate. Tonight Palin will go head to head with her Democratic counterpart, Sen. Joe Biden of Delaware.

The debate begins at 6 p.m. PDT. We'll be carrying a live feed on our homepage, and live-blogging right here.

As we wrote earlier today, this is sure to be an interesting ride, both in terms of style and substance.

As for the format, each candidate will have 90 seconds to answer questions from Gwen Ifill, the moderator who came under fire this week. Then Ifill will open up the floor for a two-minute discussion on each topic. You can learn more about the rules here.